Snap.kclock.kclockd.service fails to start

Kubuntu 22.04 LTS kclock 23.04.2 Snap starts and renders GUI but timers and alarms not available due to associated kclockd service failing to start.

Syslog error message: qt.qpa.plugin: Could not find the Qt platform plugin “xcb” in “”

Not sure if relevant but starting the app with QT_DEBUG_PLUGINS=1 only references - not